South Korean and U.S. researchers said on Wednesday they had cloned a human embryo and extracted from it sought-after cells called embryonic stem cells.
The experiment, the first published report of cloned human stem cells, means so-called therapeutic cloning is no longer a theory but a reality.
Supporters of medical cloning say it can transform medicine, offering tailored and highly effective treatments for diseases ranging from Parkinson's to diabetes. They say it could eventually lead to grow-your-own organ transplants.
The stem cells taken from the tiny embryos, known as blastocysts, have the potential to develop into any kind of cell or tissue in the body.